<html>
  <head>
  </head>
  <body>
    <script type="text/javascript">
      var ws = new WebSocket('ws://localhost:3000')
      ws.onopen = function(event) {
        ws.send('front-end message: ABC');
      };
      ws.onmessage = function(event) {
        console.log('server message: ', event.data)
      };
    </script>
  </body>
</html>